Summary: Biosensors using specific plasmon resonance (SPR) are being used by industry for assessing biochemical parameters of protein therapeutics and immunogenicity. We are working to develop more sensitive methodologies for use of this technology. This could enhance detection of immunogenicity and allow use of this technology for sensitive detection of residuals in manufacturing. Clearance studies are often restricted by low assay sensitivity. Development of more sensitive assays could facilitate demonstration of increased clearance of manufacturing contaminants.